I’ve looked through this forum and can’t seem to find anyone else with this issue. The craftbukkit server works fine. But, when trying to build the HelloWorld plugin, I get an ‘error in opening zip file’ error and compilation stops. Here’s what I copied from the shell:

Could be a corrupted jar file, I suppose. Make sure it downloaded ok. Also, the JAVA_HOME setting could be wrong. Make sure that it points to the root of the Java JDK (not the JRE, which doesn’t have the development tools). So it should be set to something like C:\Program Files (x86)\Java\jdk1.6.0_15

I created a JAVA_HOME environment variable and pointed it at my jdk folder. But that didn’t fix it.

Then, I deleted the bukkit.jar file from the server directory, re-downloaded it from the BukkitWikki page into the server directory (renamed it to bukkit.jar during the download), and it worked! Thanks so much! :)